Hi
I'm another one of the very many of us who have been through lots of different diagnoses in the DSM.
Schizoaffective's my current label (although they recently added 'with dissociative traits' to it). I've also had schizophrenia, psychotic illness, bipolar, borderline personality disorder, depression and a few others that I can't quite remember.
Throughout all this time I haven't changed (well, no more than anyone changes as they grow and learn to deal with things differently). The diagnostic system is flawed to say the least. And yes, if a different diagnosis means a different plan of support and/or treatment - it's a little worrying.
Schizoaffective disorder, as diagnoses go, isn't a bad one. I think of it as the multivalue pack of mental distress. They're not pretending it actually exists as a biological illness, as far as I'm aware, but see it more as a grouping of 'symptoms' or experiences. These are, as you probably already know, the psychosis (ie voices, visions, unusual beliefs) and the mood swings (the bipolar bit). I think there's also a clause in there that means you have to have some of the psychosis when you're not experiencing the mood swings ... but I can't remember the exactness of that.
I was prescribed an antipsychotic, a mood stabiliser and an antidepressant for years with this (the idea, I think, was to treat each aspect of the thing).
Still, I honestly believe that it's more helpful for me to see my experiences in terms of what they are at that moment (and not worry too much about the diagnosis that may or may not change). It helps keep me rooted. I go up (the highs), down (the lows) and sideways (the psychosis). I also experience anxiety. I'm working out ways of dealing with all of them (yay).
A diagnosis made me feel better for the first year or so, but after that I realised that (for me) it was a much bigger burden than help.
Take care x PMG